This invention relates to deadbolt door lock assemblies, and in particular to such a door lock assembly in which the deadbolt is configured for keyless operation to lock the deadbolt.
Deadbolt door lock assemblies are commonly installed on entry doors of commercial and residential buildings to lock the doors closed and to provide increased security against unwanted entry. In such lock assemblies, a deadbolt is selectively positionable between an unlocked position and a locked position. In the unlocked position, the deadbolt is recessed into the door, allowing the door to open. In the locked position, the deadbolt extends out from the door for disposition within an opposing door frame jamb (when the door is closed), thereby locking the door closed.
Single cylinder and double cylinder deadbolt lock assemblies may be used. Both generally include an oscillating crank to actuate the deadbolt between the unlocked and locked positions. In the single cylinder assembly, a torque blade connects the crank to a thumbturn mounted on the inside facing surface of the door (e.g., accessible from within the building) and to a lock cylinder accessible from the outside surface of the door. The thumbturn can be manually turned or a key can be used to operate the lock cylinder to rotate the torque blade and actuate the deadbolt between its unlocked and locked positions. In the double cylinder assembly, the torque blade operatively connects the crank to two lock cylinders, one on each of the inside and outside surfaces of the door. Keys are used with both lock cylinders to operate the deadbolt.
While it is known that deadbolt door locks provide improved security, people often do not use them after closing the door from outside because it requires finding the correct key to operate the lock cylinder. To remedy this, some deadbolt lock assemblies allow keyless locking operation from outside the door to lock the deadbolt. Examples are disclosed in U.S. Pat. No. 3,593,548 (Kendrick), U.S. Pat. No. 5,010,749 (Lin), U.S. Pat. No. 5,150,592 (Lin), U.S. Pat. No. 5,186,030 (Lin), and U.S. Pat. No. 5,797,286 (Armstrong). These deadbolt door lock assemblies typically include a ring surrounding the lock cylinder in operative connection with the torque blade to actuate the deadbolt to its locked position without having to use a key.
One drawback of these prior deadbolt door lock assemblies is that they are susceptible to binding or jamming during subsequent unlocking of the deadbolt. In particular, the ring tends to interfere with the rotation of the torque blade back to a position corresponding to the unlocked position of the deadbolt. In addition, the force necessary to overcome binding of the lock accelerates wear of the internal mechanisms of the assembly. Another disadvantage of some prior keyless deadbolt lock devices is that projection of the deadbolt may be dependent on the rotational speed imparted by the user to the ring. In such a design, the deadbolt may not fully project to its locked position, leaving the lock easily retracted without a key.
To this end, co-assigned U.S. Pat. Nos. 5,813,261 and 6,601,420, the entire disclosures of which are incorporated by reference herein, disclose keyless deadbolt door lock assemblies that inhibit binding upon unlocking of the deadbolt. In particular, the keyless ring is used to actuate the torque blade to move the deadbolt to its locked position, and is then returned to its initial position by a biasing member so that the ring cannot interfere with subsequent movement of the torque blade (e.g., by using a key) back to the unlocked position of the deadbolt.
However, the lock assemblies disclosed in these references are generally useable on only a left hand door or a right hand door. Thus, two different models must be made available (one for use with a left hand door and one for use with a right hand door). Alternatively, the disclosed lock assembly may be disassembled, substantially reconfigured and reassembled to switch from use on a left hand door to use on a right hand door (or vice-versa).
There is a need, therefore, for a keyless deadbolt door lock assembly which is operable on either a left hand door or a right hand door with little or no reconfiguration, and is less susceptible to binding during unlocking of the deadbolt.